This invention relates to a coating composition and in particular to a coating composition of a polysulfone resin.
Industry requires finishes that are tough, durable and scratch resistant and are thermally stable for equipment subjected to heat such as household and industrial ovens. Home and industrial bakeware and cookware require finishes that have food release properties and thermal stability. Also, the exterior areas of cookware such as fry pans, covers for fry pans, the sides and bottoms of electric cooking appliances require finishes that are tough, durable, thermally stable, and have release properties. Finishes of polysulfone resins meet some of these requirements. Polysulfone resins are well known in the art as shown by Vogel U.S. Pat. No. 3,321,449, issued May 23, 1967; D'Alessandro U.S. Pat. No. 3,355,272, issued Nov. 28, 1967; Cohen et al. U.S. Pat. No. 3,518,235, issued June 30, 1970; Pietrusza et al. U.S. Pat. No. 3,536,665, issued Oct. 27, 1970. However, it has not been possible to form high quality release coatings from these resins. Dispersions of polyarysulfones and fluorinated polyphenylene oxide polymers are shown in Whittemore et al. U.S. Pat. No. 3,471,587, issued Oct. 7, 1969 but these dispersions do not form the high quality finishes that are required for many uses.
The novel coating composition of this invention has excellent adhesion to all types of substrates and is tough, durable and thermally stable and has excellent release properties.